Yellow-billed Loon, Gavia adamsii

This
Yellow-billed Loon in molt from breeding plumage showed up in one of the salt ponds along the
southern end of San Francisco Bay in October 2011, where it was seen
and
photographed by many Bay Area
birders. It was a great rarity for the spot, but its location and
behavior raised fears that it might be sick or injured. Sadly, these
fears were realized when the bird died about a week after this photo
was taken. Yellow-billed Loons closely resemble the familiar Common Loon
but live further north, breeding on tundra ponds along the shore of the
Arctic
Ocean, and normally wintering on coastal bays in Alaska and Norway; the
light-colored bill is the best mark distinguishing the two species.